Chlorogenic acid oxidation-induced greening of sunflower butter cookies as a function of different sweeteners and storage conditions

Abstract

Sunflower butter use as an allergen-free alternative to tree and legume nut butter in baking is limited by chlorogenic acid induced greening that occurs at alkaline pH. Limited information is available on controlling this greening in a food matrix. This study examined how different liquid sweeteners and relative humidity influenced greening of sunflower butter cookies. Doughs had similar initial pH (7.52-7.66) which increased to 8.44-9.13 after baking as ranked: xylitol>maple syrup>corn syrup>honey>agave syrup. Cookies made with maple syrup had the highest moisture and greening corresponding with lowest free chlorogenic acid. The % greening followed the same trend as greening intensity, and was positively correlated (r=0.9101) with chlorogenic-lysine adduct content. Our findings provide an ingredient solution to controlling greening, as results demonstrate that greening can be promoted with high relative humidity storage, and use of high moisture and pH ingredients. Unwanted greening can be inhibited by simply changing the liquid sweetener.

Covalent Bonding of Chlorogenic Acid Induces Structural Modifications on Sunflower Proteins

“…It is important to mention that pure sunflower proteins exhibit valuable functional properties (solubility, interfacial activity) . However, when covalently complexed with CGA they become insoluble, indigestible and appear with a green color which hampers their potential applications as food or drug ingredient . Nonetheless, CGA is also a biofunctional compound for food and drug applications .…”

“…[13] However,w hen covalently complexed with CGA they becomei nsoluble,i ndigestible and appear with ag reen color which hampers their potential applications as food or drug ingredient. [14][15][16] Nonetheless, CGA is also abiofunctional compound for food and drug applications. [17,18] Therefore current valorizationp rocedures are often aimed at obtaining the proteins and/or CGA in ap ure form whichd id not find industrial applications, [19] since, duet o their high reactivity formation of complexesb etween the two is hardly avoidable.…”

Lowering greening of cookies made from sunflower butter using acidic ingredients and effect on reducing capacity, tryptophan and protein oxidation

“…Greening was measured using a spectrophotometer (CM-2500d) equipped with SpectraMagic NX ® colour data software (Konica Minolta, Inc. CA. USA) with the CIE L*a*b* system as described by Were (2018a and2018b) The percentage greening of cookies was carried out using an image analyzer (Keyence Corporation, CA. USA) equipped with a camera (CV-X422A) which had 2.0 megapixel.…”

“…90 mm), and then filtered, with a 0.45 µm nylon syringe filter. The CGA of the supernatant was quantified, as decribed by Liang and Were (2018b). Chlorogenic acid-lysine standard solutions were prepared according to our previous study (Liang & Were, 2018b) and…”

“…This high CGA content results in green to blue pigment formation when CGA dimerizes with itself under alkaline conditions. The CGA dimer then oxidizes to form highly reactive o-quinones which can subsequently react with amino acids in an aqueous, alkaline environment to form green trihydroxy benzacridine (TBA) derivatives (Liang & Were, 2018a, 2018b. The rate of greening increases with pH and heat, which can limit the application of sunflower butter in bakery applications (Wildermuth, Young, & Were, 2016).…”